31991999490 has 192 divisors, whose sum is σ = 93963542400. Its totient is φ = 7739867520.

The previous prime is 31991999489. The next prime is 31991999503. The reversal of 31991999490 is 9499919913.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 28847056 + ... + 28848164.

It is an arithmetic number, because the mean of its divisors is an integer number (489393450).

Almost surely, 2^31991999490 is an apocalyptic number.

31991999490 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 31991999490, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46981771200).

31991999490 is an abundant number, since it is smaller than the sum of its proper divisors (61971542910).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31991999490 is a wasteful number, since it uses less digits than its factorization.

31991999490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2030 (or 2013 counting only the distinct ones).

The product of its (nonzero) digits is 6377292, while the sum is 63.

The spelling of 31991999490 in words is "thirty-one billion, nine hundred ninety-one million, nine hundred ninety-nine thousand, four hundred ninety".